Spinal surgeries often require precision drilling and placement of screws or other implements in bone tissue. Catastrophic damage or death may result from improper drilling or maneuvering of the body during spinal surgery due to the proximity of the spinal cord and arteries. Further, accurate placement is typically necessary for a successful outcome. For example, spinal fusion is typically augmented by stabilizing the vertebrae with fixation devices, such as metallic screws, rods, and plates, to facilitate bone fusion. In spinal fusion, as well as other surgeries, the accuracy with which the screws are placed in the bone has a direct effect on the outcome of the procedure. The less motion there is between the two bones trying to heal, the higher the change the bones will successfully fuse. The use of fixation devices has increased the success rate of spinal fusion procedures considerably.
Such procedures rely strongly on the expertise of the surgeon, and there is significant variation in success rate among different surgeons. A number of navigational and verification approaches have been developed. However, screw misplacement is still a common problem in such surgical procedures. Screws may be misaligned due to inaccurate holes drilled prior to inserting the screw. The angle of the tip of the drill may cause the drill bit to skid as the tip contacts the bone tissue, thereby causing the hole to be drilled along an incorrect trajectory. Typically, unless a bone drill is driven at 90 degrees to the bone surface there is a tendency for the drill bit to skid over the bone surface thereby placing the hole inappropriately. Thus, there is a need for an anti-skid surgical instrument for preparing holes in a patient's bone while minimizing the risk of the instrument skidding upon contact of the surgical instrument with the bone.